Hybrid Drivetrain Separating Clutch for Quiet Electric Shifting

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Solution Overview

Problem

Existing hybrid drive trains face issues such as damage to the combustion engine and catalytic converter, complex control systems, high demands on the combustion engine, and additional inertia during gear engagement when the electric machine is arranged between the internal combustion engine and transmission, leading to inefficiencies and noise concerns during purely electrical operation.

Innovation Solution

A hybrid drive train design with a third friction clutch arranged radially between the dual clutch transmission and the internal combustion engine, utilizing a dual-mass flywheel or connecting element, and actuated via a switching sleeve and shift rod for compact integration and simplified operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the electric machine is arranged between the internal combustion engine and the transmission, then the gear stages can be used at least partially by the electric machine, but the combustion engine must be brought up to speed in the unfired state and carried along during gear shifting, leading to damage risk, complex regulation, and additional inertia

Engineering Contradiction:
Improvegear stage utilizationVSAvoidengine damage risk
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The drivetrain is segmented into two independent power flow paths: one through the dual-clutch transmission for electric/combined operation, and another through the third clutch and separating element for direct engine-to-transmission connection. This segmentation allows the engine to be decoupled during electric operation, preventing damage while maintaining gear stage utilization capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The third clutch acts as an intermediary component between the dual-clutch transmission and the internal combustion engine. It enables selective engagement/disengagement of the engine from the transmission, allowing the electric machine to operate independently without dragging the engine along during gear shifts, thus preventing damage while maintaining adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a third clutch is added to separate the combustion engine from the transmission, then the combustion engine can be separated during electric operation, but the installation space is very limited and additional weight and complexity are introduced

Engineering Contradiction:
Improveengine separation capabilityVSAvoidclutch actuation mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The third clutch is merged with the existing dual-mass flywheel assembly, utilizing the same radial space and mounting structure. The separating element is integrated into the flywheel's radial architecture, combining the functions of vibration damping, inertia management, and engine separation into a single compact unit, thereby reducing overall device complexity despite adding separation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The third clutch separating element is nested within the radial space of the dual-mass flywheel assembly. The actuation mechanism is integrated into the existing clutch housing structure, with the separating element fitting within the radial dimensions already allocated for the dual-clutch system, effectively nesting the new functionality within existing spatial constraints.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Volume of moving object

If the third clutch is arranged radially between the dual-clutch transmission and the internal combustion engine, then compact integration is achieved, but the drag torques when disengaged should be avoided

Engineering Contradiction:
Improveclutch arrangement compactnessVSAvoiddrag torque
Core Design Contradiction:
Volume of moving objectVSLoss of energy

Solution Approach 1:

The separating element is designed to completely disengage the internal combustion engine from the transmission when the third clutch is actuated. By extracting the engine connection entirely rather than maintaining partial engagement, drag torques are eliminated during electric operation, while the radial arrangement maintains compact integration.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables a compact, efficient, and low-weight design that reduces the risk of engine damage, simplifies control, and minimizes noise during electric operation by allowing the combustion engine to be separated from the transmission, thereby optimizing power flow and reducing torque compensation demands.

Implementation Method 1

downstream of the internal combustion engine in the drive system is a torsional vibration damper designed as a dual-mass flywheel for vibration damping in the drive train

Methodology Applied
Scientific EffectTorsional vibration damping: Damping

Implementation Method 2

a third friction clutch is arranged between the dual clutch transmission and the internal combustion engine

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4107020B1Hybrid drivetrain for a motor vehicle with separating element
Publication Date: 2024.08.07 MAGNA PT B V & CO KG
  • EP4107020B1 patent drawingFigure 1~2
  • EP4107020B1 patent drawingFigure 3
  • EP4107020B1 patent drawingFigure 4

AI summary

The invention relates to a hybrid drivetrain for a motor vehicle, wherein the hybrid drivetrain (10) has an internal combustion engine (VM), a double-clutch transmission and an electric machine (EM), wherein the double-clutch transmission has a first and a second friction clutch (20, 18) and a first and a second sub-transmission (TG1, TG2), the electric machine (EM) being associated with one of the sub-transmissions (TG1, TG2), and wherein a third clutch is arranged between the two friction clutches (18, 20) and the internal combustion engine (VM), the third clutch being a separating element (60) that is attached to the clutch input hub (14) of the double clutch (12), radially between a dual mass flywheel (80) and the clutch input hub (14).